CN1172326C - Magnet powder and isotropic bound magnet - Google Patents

Magnet powder and isotropic bound magnet Download PDF

Info

Publication number
CN1172326C
CN1172326C CNB011108142A CN01110814A CN1172326C CN 1172326 C CN1172326 C CN 1172326C CN B011108142 A CNB011108142 A CN B011108142A CN 01110814 A CN01110814 A CN 01110814A CN 1172326 C CN1172326 C CN 1172326C
Authority
CN
China
Prior art keywords
ferromagnetic powder
binding magnet
magnet
atom
mentioned
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
CNB011108142A
Other languages
Chinese (zh)
Other versions
CN1304144A (en
Inventor
�¾�ʥ
新井圣
加藤洋
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Seiko Epson Corp
Original Assignee
Seiko Epson Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Seiko Epson Corp filed Critical Seiko Epson Corp
Publication of CN1304144A publication Critical patent/CN1304144A/en
Application granted granted Critical
Publication of CN1172326C publication Critical patent/CN1172326C/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
    • H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
    • H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
    • H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
    • H01F1/04—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
    • H01F1/047—Alloys characterised by their composition
    • H01F1/053—Alloys characterised by their composition containing rare earth metals
    • H01F1/055—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5
    • H01F1/057—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
    • H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
    • H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
    • H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
    • H01F1/04—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
    • H01F1/047—Alloys characterised by their composition
    • H01F1/053—Alloys characterised by their composition containing rare earth metals
    • H01F1/055—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5
    • H01F1/057—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B
    • H01F1/0579—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B with exchange spin coupling between hard and soft nanophases, e.g. nanocomposite spring magnets
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y25/00—Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
    • H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
    • H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
    • H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
    • H01F1/04—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
    • H01F1/047—Alloys characterised by their composition
    • H01F1/053—Alloys characterised by their composition containing rare earth metals
    • H01F1/055—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5
    • H01F1/057—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B
    • H01F1/0571—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes
    • H01F1/0575—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes pressed, sintered or bonded together
    • H01F1/0578—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes pressed, sintered or bonded together bonded together

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Inorganic Chemistry (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Power Engineering (AREA)
  • Nanotechnology (AREA)
  • Composite Materials (AREA)
  • Hard Magnetic Materials (AREA)
  • Powder Metallurgy (AREA)
  • Manufacture Of Metal Powder And Suspensions Thereof (AREA)

Abstract

The invention provides a magnetic powder which can provide a bonded magnet having excellent magnetic properties and having excellent reliability especially excellent heat stability. The magnetic powder of the invention is composed of an alloy composition represented by Rx(Fe1-yCoy)100-x-z-wBzNbw (where R is at least one kind of rare-earth element, x is 7.1-9.9 at %, y is 0-0.30, z is 4.6-6.9 at %, and w is 0.2-3.5 at %), the magnetic powder being constituted from a composite structure having a soft magnetic phase and a hard magnetic phase, wherein the magnetic powder has magnetic properties in which, when the magnetic powder is formed into an isotropic bonded magnet having a density rho [Mg/m3] by mixing with a binding resin and then molding it, the maximum magnetic energy product (BH)max[kJ/m3] of the bonded magnet at the room temperature satisfies the relationship represented by the formula (BH)max/rho2[x10-9J.m3/g2]>=2.2, and the intrinsic coercive force (HCJ) of the bonded magnet at the room temperature is in the range of 320-720 kA/m.

Description

Ferromagnetic powder and isotropism binding magnet
Technical field
The invention relates to ferromagnetic powder and isotropism binding magnet.
Background technology
In order to seek the miniaturization of motor etc., the magnetic flux density height of (in the magnetic conductivity of the essence) magnet when wishing in this motor, to use.The factor of the magnetic flux density of decision binding magnet has the magnetization value of ferromagnetic powder and the content (containing ratio) of the ferromagnetic powder in the binding magnet.Therefore, under the so not high situation of the magnetization of ferromagnetic powder self, the content of the ferromagnetic powder in the binding magnet just can not get sufficient magnetic flux density if not very many.
, the magnet that uses as the high-performance rare-earth binding magnet as the rare-earth magnet powder, uses the isotropism binding magnet of the MQP-B powder of MQI company manufacturing to account for most at present.The isotropism binding magnet has following advantage than anisotropic bond magnet.That is, when making binding magnet, do not need magnetic field orientating, so manufacture process is simple, its result is cheap for manufacturing cost.But with this MQP-B powder is that the existing isotropism binding magnet of representative exists following problem.
1) in existing isotropism binding magnet, magnetic flux density is inadequate.The magnetization that is employed ferromagnetic powder is low, thereby must improve the content (containing ratio) of the ferromagnetic powder in the binding magnet, if but the content of raising ferromagnetic powder, the formability of binding magnet just worsens, thereby content is restricted.In addition, even by molding condition being taken measures etc., the content of ferromagnetic powder is increased, resulting magnetic flux density is still very limited, therefore can not seek the miniaturization of motor.
2) also once reported the high magnet of residual magnetic flux density in nano-composite magnet, but this moment, coercive force was too small on the contrary, the magnetic flux density that obtains as motor in the practicality (magnetic conductivity when using in the reality) is very low.In addition, because coercive force is little, so thermal stability is also poor.
3) corrosion resistance of binding magnet, thermal endurance are low.That is, for the magnetic property that remedies ferromagnetic powder is low, the content of the ferromagnetic powder in the binding magnet is increased (that is, making the density densification terrifically of binding magnet), its result, corrosion resistance, the thermal endurance of binding magnet are inferior, and reliability is also low.
Summary of the invention
The objective of the invention is to, provide can make have excellent magnetic characteristics, the ferromagnetic powder and the isotropism binding magnet of reliability, magnet that especially temperature characterisitic is good.
In order to achieve the above object, the invention relates to ferromagnetic powder, this ferromagnetic powder is by with R x(Fe 1-yCo y) 100-x-z-wB zNb w(R is at least a rare earth element, x:7.1～9.9 atom %, y:0～0.30, z:4.6～6.9 atom %, w:0.2～3.5 atom %) alloy composition of expression constitutes, have soft magnetism phase and hard magnetic complex tissue mutually, it is characterized in that, forming density p [Mg/m with forming after binder resin mixes 3] the isotropism binding magnet time, the maximum magnetic energy product under the room temperature (BH) max[kJ/m 3] satisfied (BH) max/ ρ 2[* 10 -9Jm 3/ g 2The relation of] 〉=2.2, and the intrinsic coercive force H under the room temperature CJBe 320～720kA/m.
Adopt above-mentioned ferromagnetic powder, can provide have excellent magnetic characteristics, good magnet such as thermal endurance (thermal stability), corrosion resistance.
Among the present invention, forming density p [Mg/m with forming after binder resin mixes 3] the isotropism binding magnet time, the residual magnetic flux density Br[T under the room temperature] preferably satisfy Br/ ρ [* 10 -6Tm 3/ g] 〉=0.125 relation.
Thus, magnetic property, thermal endurance (thermal stability), corrosion resistance etc. are improved more.
Other aspects of the present invention are about ferromagnetic powder, and this ferromagnetic powder is by with R x(Fe 1-yCo y) 100-x-z-wB zNb w(R is at least a rare earth element, x:7.1～9.9 atom %, y:0～0.30, z:4.6～6.9 atom %, w:0.2～3.5 atom %) alloy composition of expression constitutes, have soft magnetism phase and hard magnetic complex tissue mutually, it is characterized in that, forming density p [Mg/m with forming after binder resin mixes 3] the isotropism binding magnet time, the residual magnetic flux density Br[T under the room temperature] preferably satisfy Br/ ρ [* 10 -6Tm 3/ g] 〉=0.125 relation.
Adopt above-mentioned ferromagnetic powder, can provide have excellent magnetic characteristics, good magnet such as thermal endurance (thermal stability), corrosion resistance.
This ferromagnetic powder, with form when forming the isotropism binding magnet the intrinsic coercive force H under the room temperature after binder resin mixes CJ320～720kA/m preferably.Like this,, also can carry out good magnetization, obtain sufficient magnetic flux density even can not get sufficient magnetizing field.
In addition, in the present invention, above-mentioned ferromagnetic powder, with form after resin mixes when forming the isotropism binding magnet, the absolute value of irreversible demagnetization rate (initial stage demagnetization rate) is preferably below 6.2%.Thermal endurance (thermal stability) becomes good especially thus.
In above occasion, preferably above-mentioned R is the rare earth element based on Nd and/or Pr.Thus, improve the saturation magnetization of the hard magnetic phase that constitutes complex tissue (nano combined especially tissue), coercive force is better.
In addition, above-mentioned R comprises Pr, and above-mentioned relatively R is all, and its ratio is 5～75%.Thus, residual magnetic flux density reduces hardly, can improve coercive force and rectangularity.
And then above-mentioned R comprises Dy, and above-mentioned relatively R is all, and its ratio is below 14%.Thus, do not follow residual magnetic flux density to reduce significantly, can improve coercive force and thermal endurance (thermal stability).
In addition, in the present invention, above-mentioned ferromagnetic powder preferably obtains by chilling liquation alloy.Thus, metal structure (crystal grain) refinement can be made with comparalive ease, magnetic property can be further improved.
In addition, this ferromagnetic powder preferably will use the chilling strip pulverizing of chill roll manufacturing to obtain.Thus, metal structure (crystal grain) refinement can be made with comparalive ease, magnetic property can be further improved.
In addition, above-mentioned ferromagnetic powder preferably carries out at least 1 heat treatment in its manufacture process or after making.Thus, homogenizing takes place in tissue, perhaps removes by the influence of pulverizing the strain of introducing, and further improves magnetic property.
Above-mentioned ferromagnetic powder, preferably average grain diameter is 0.5～150 μ m.Thus, can make magnetic property good especially.In addition, when in the manufacturing of binding magnet, using, obtain content (containing ratio) height of ferromagnetic powder, the binding magnet that has excellent magnetic characteristics.
Another aspect of the present invention is about the isotropism binding magnet, and this magnet is will contain the ferromagnetic powder bonding of Nb and the isotropism binding magnet that constitutes with binder resin, it is characterized in that, and be ρ [Mg/m in the density of isotropism binding magnet 3] time, the maximum magnetic energy product under the room temperature (BH) max[kJ/m 3] satisfied (BH) max/ ρ 2[* 10 -9Jm 3/ g 2The relation of] 〉=2.2, and the intrinsic coercive force H under the room temperature CJBe 320～720kA/m.
According to above-mentioned formation, can provide have excellent magnetic characteristics, good isotropism binding magnet such as thermal endurance (thermal stability), corrosion resistance.
In this occasion, the residual magnetic flux density Br[T under the room temperature] preferably satisfy Br/ ρ [* 10 -6Tm 3/ g] 〉=0.125 relation.
Thus, make magnetic property, thermal endurance (thermal stability), corrosion resistance etc. good especially.
Another aspect of the present invention is about the isotropism binding magnet, and this magnet is will contain the ferromagnetic powder bonding of Nb and the isotropism binding magnet that constitutes with binder resin, it is characterized in that, and be ρ [Mg/m in the density of isotropism binding magnet 3] time, the residual magnetic flux density Br[T under the room temperature] preferably satisfy Br/ ρ [* 10 -6Tm 3/ g] 〉=0.125 relation.
According to above-mentioned formation, can provide have excellent magnetic characteristics, good isotropism binding magnet such as thermal endurance (thermal stability), corrosion resistance.
In this occasion, the intrinsic coercive force H under the room temperature CJ320～720kA/m preferably.Thus,, also can carry out good magnetization, obtain sufficient magnetic flux density even can not get sufficient magnetizing field.
In this isotropism binding magnet, above-mentioned ferromagnetic powder is that alloy (R is at least a kind of rare earth element, and TM is the transition metal based on iron) constitutes by R-TM-B-Nb preferably.Thus, magnetic property, thermal endurance (thermal stability), corrosion resistance etc. become good especially.
In addition, in this isotropism binding magnet, above-mentioned ferromagnetic powder is preferably by with R x(Fe 1-yCo y) 100-x-z-wB zNb wThe alloy composition of (R is at least a rare earth element, x:7.1～9.9 atom %, y:0～0.30, z:4.6～6.9 atom %, w:0.2～3.5 atom %) expression constitutes.Thus, magnetic property, thermal endurance (thermal stability), corrosion resistance etc. become good especially.
In addition, in this isotropism binding magnet, above-mentioned R is preferably based on the rare earth element of Nd and/or Pr.Thus, coercive force is better.
In this occasion, above-mentioned R preferably includes Pr, and above-mentioned relatively R is all, and its ratio is 5～75%.Thus, residual magnetic flux density reduces hardly, can improve coercive force and rectangularity.
In addition, above-mentioned R preferably includes Dy, and above-mentioned relatively R is all, and its ratio is below 14%.Thus, do not follow the remarkable reduction of residual magnetic flux density, can improve coercive force and thermal endurance (thermal stability).
In addition, above-mentioned isotropism binding magnet, the average grain diameter of best above-mentioned ferromagnetic powder is 0.5～150 μ m.Thus, the isotropism binding magnet that can provide the content (containing ratio) of ferromagnetic powder high, have excellent magnetic characteristics.
In addition, above-mentioned isotropism binding magnet, preferably the absolute value of irreversible demagnetization rate (initial stage demagnetization rate) is below 6.2%.Thus, thermal endurance (thermal stability) becomes good especially.
In addition, in above-mentioned isotropism binding magnet, above-mentioned ferromagnetic powder preferably constitutes with hard magnetic complex tissue mutually mutually by having soft magnetism.Thus, when improving magnetizability, improve thermal endurance (thermal stability), magnetic property is over time little.
In addition, above-mentioned isotropism binding magnet is preferably supplied with multipole magnetized, perhaps by multipole magnetized.Thus,, also can form good magnetization, thereby obtain sufficient magnetic flux density even when can not get sufficient magnetizing field.
And then above-mentioned isotropism binding magnet is preferably used in motor.Thus, can access small-sized and high performance motor.
Other purposes of the present invention, formation and effect can be clear from the explanation of following embodiment.
Description of drawings
Fig. 1 is the figure that schematically represents an example of the complex tissue (nano combined tissue) in the ferromagnetic powder of the present invention.
Fig. 2 is the figure that schematically represents an example of the complex tissue (nano combined tissue) in the ferromagnetic powder of the present invention.
Fig. 3 is the figure that schematically represents an example of the complex tissue (nano combined tissue) in the ferromagnetic powder of the present invention.
Fig. 4 is the oblique view of the configuration example of the expression device (chilling strip manufacturing installation) of making ferromagnetic material.
Fig. 5 is near the section side view of the state of alloy liquation chill roll carries out colliding part in presentation graphs 4 shown devices.
Below, explain the execution mode of ferromagnetic powder of the present invention and isotropism binding magnet.
Embodiment
In order to seek miniaturizations such as motor, obtain the high magnet of magnetic flux density, just become problem.The factor of the magnetic flux density in the decision binding magnet has the magnetization value of ferromagnetic powder and the content (containing ratio) of the ferromagnetic powder in the binding magnet.But under the so not high situation of the magnetization of ferromagnetic powder self, the content of the ferromagnetic powder in the binding magnet just can not get sufficient magnetic flux density if not very many.
The MQP-B powder that the above-mentioned MQI company that has popularized now makes, as mentioned above, according to purposes, magnetic flux density is inadequate.Therefore, when making binding magnet, improve the content of the ferromagnetic powder in the binding magnet, promptly have no alternative but carry out densification, when aspects such as corrosion resistance, thermal endurance or mechanical strength lack reliability, because the coercive force height, so the shortcoming that has magnetizability to worsen.
In contrast, ferromagnetic powder of the present invention and isotropism binding magnet obtain the coercive force of sufficient magnetic flux density and appropriateness.Thus, the content of the ferromagnetic powder in the binding magnet (containing ratio) is unnecessary to be brought up to so highly, and its result can provide the binding magnet that high strength and formability, corrosion resistance, magnetizability etc. are good, reliability is high.In addition, because miniaturization, the high performance of binding magnet, also can make big contribution to the miniaturization of the device of loading magnet such as motor.
In addition, ferromagnetic powder of the present invention can constitute and has soft magnetism mutually and hard magnetic complex tissue mutually.
The MQP-B powder that above-mentioned MQI company makes is the homogeneous structure of hard magnetic phase, in such complex tissue, has the high soft magnetism phase of magnetization.Therefore the high advantage of total magnetization is arranged, and then because bounce-back permeability height, so even apply opposite magnetic fields, demagnetization rate after this is also very little.
The alloy composition of ferromagnetic powder
Ferromagnetic powder of the present invention is the ferromagnetic powder that alloy (R is at least a rare earth element, and TM is the transition metal based on iron) constitutes by R-TM-B-Nb preferably.Wherein, especially preferably with by R x(Fe 1-yCo y) 100-x-z-wB zNb wThe ferromagnetic powder that the alloy composition of (R is at least a rare earth element, x:7.1～9.9 atom %, y:0～0.30, z:4.6～6.9 atom %, w:0.2～3.5 atom %) expression constitutes.
As R (rare earth element), can enumerate Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, mishmetal, can contain in them more than a kind or 2 kinds.
The content of R (containing ratio) is defined as 7.1～9.9 atom %.During less than 7.1 atom %, can not get sufficient coercive force at R, even add Nb, coercitive raising is also few.On the other hand, if R surpasses 9.9 atom %, magnetized potential can reduce, and therefore can not get sufficient magnetic flux density.
R is preferably based on the rare earth element of Nd and/or Pr.Its reason is, these rare earth elements improve the saturation magnetization of the hard magnetic phase that constitutes complex tissues (especially nano combined tissue), and as magnet to realizing that good coercive force is effective.
In addition, above-mentioned R comprises Pr, and above-mentioned relatively R is all, and its ratio better is 5～75%, preferably 20～60%.If this scope, residual magnetic flux density just reduces hardly, therefore can improve coercive force and rectangularity.
In addition, R comprises Dy, and above-mentioned relatively R is all, and its ratio is preferably below 14%.If this scope, residual magnetic flux density just reduces indistinctively, can improve coercive force, simultaneously, makes the raising of temperature characterisitic (thermal stability) also become possibility.
Co is the transition metal with characteristic identical with Fe.By adding Co (part that replaces Fe), Curie temperature is uprised, and improve temperature characterisitic, if but Co surpasses 0.30 to the replacement ratio of Fe, and the tendency that coercive force, magnetic flux density reduce simultaneously appears.In 0.05～0.20 scope, not only temperature characterisitic improves Co to the replacement ratio of Fe, and magnetic flux density itself also improves, and is best therefore.
B (boron) is in order to obtain the effective element of high magnetic characteristics, and its content is defined as 4.6～6.9 atom %.If B is less than 4.6 atom %, the rectangularity of B-H (J-H) loop line just worsens.On the other hand, if B ultrasonic is crossed 6.9 atom %, non magnetic phase transformation is many, and magnetic flux density just sharply reduces.
Nb is favourable element to improving coercive force, especially in the scope of 0.2～3.5 atom %, occurs the effect that coercive force improves significantly.In addition, in this scope, follow coercive force and improve, rectangularity and maximum magnetic energy product also improve.And it is good that thermal endurance and corrosion resistance also become.But, as mentioned above, at R during, be very little by adding this effect that Nb produces less than 7.1 atom %.In addition, if Nb surpasses 3.5 atom %, magnetization just takes place reduce.
Moreover, though Nb itself is not new material, but the inventor has carried out experiment, research repeatedly, found that, by have soft magnetism mutually with ferromagnetic powder that hard magnetic complex tissue mutually constitutes in, contain Nb by scope, can obtain following three kinds of effects: 1. both guaranteed good rectangularity, maximum magnetic energy product, and reached coercitive raising again at 0.2～3.5 atom %; 2. reach improve (the absolute value reduction) of irreversible demagnetization rate; 3. can keep good corrosion resistance, especially can obtain these effects simultaneously, this is a meaning of the present invention.
The optimum range of Nb content as mentioned above, is 0.2～3.5 atom %, and the higher limit of this scope better is 3.0 atom %, preferably 2.5 atom %.
In addition, more to improve magnetic property etc. is purpose, in the alloy that constitutes ferromagnetic powder, as required, can also contain at least a element of from the group (following this group is with " Q " expression) that Al, Cu, Si, Ga, Ti, V, Ta, Zr, Mo, Hf, Ag, Zn, P, Ge, Cr, W form, selecting.When containing the element that belongs to Q, its content better is below the 2 atom %, is more preferably 0.1～1.5 atom %, preferably 0.2～1.0 atom %.
Contain the element that belongs to Q, according to the intrinsic effect of its kind performance.For example, Al, Cu, Si, Ga, V, Ta, Zr, Cr have the corrosion proof effect of raising.
Complex tissue
In addition, ferromagnetic material forms and has soft magnetism phase and hard magnetic complex tissue mutually.
The soft magnetism of this complex tissue (nano combined tissue) 10 11 for example exists with Fig. 1, Fig. 2 or pattern (apperance) shown in Figure 3 with hard magnetic mutually mutually, and the thickness of each phase or particle diameter are with nanoscale (for example 1～100nm) existence.So, soft magnetism mutually 10 with hard magnetic 11 adjacent (also comprising) mutually, the reciprocation of generation magnetic by the adjacent situation of crystal boundary.Fig. 1～pattern shown in Figure 3 is an example, but is not limited to these patterns, for example in pattern shown in Figure 2, soft magnetism mutually 10 with hard magnetic mutually 11 also can become opposite.
The magnetization of soft magnetism phase, the effect by the external magnetic field changes its orientation easily, exists if therefore mix in mutually at hard magnetic, and all magnetization curve of system is at " the snake type curve " of second quadrant formation section of having of B-H figure.But, be ten minutes hour below the number 10nm in the size of soft magnetism phase, the magnetization of soft-magnetic body is subjected to very strong constraint owing to combine with the magnetization of on every side Hard Magnetic gonosome, and system is all as the hard magnetic body action.
Magnet with such complex tissue (nano combined tissue) mainly has the following feature of enumerating 1)～5).
1) at second quadrant of B-H figure (J-H figure), reversibly resilience (being also referred to as " spring magnet " according to this meaning) takes place in magnetization.
2) magnetizability is good, can be with lower magnetic field magnetisation.
3) temperature dependency of the magnetic property occasion mutually more independent than hard magnetic is little.
4) magnetic property is over time little.
5) even micro mist is broken, magnetic property is deterioration not also.
In above-mentioned alloy composition, hard magnetic mutually and soft magnetism for example become mutually as following hard magnetic phase and soft magnetism mutually.
Hard magnetic phase: R 2TM 14B is (TM is Fe or Fe and Co) or R 2(TM, Nb) 14(the perhaps R of B system 2(TM, Q) 14B system, R 2(TM, Nb, Q) 14B system)
Soft magnetism phase: TM (especially the compound of α-Fe, α-(Fe, Co)) or TM and alloy phase, TM and the B of Nb mutually, the compound phase (perhaps these comprise the phase of Q) of TM and B and Nb
The manufacturing of ferromagnetic powder
Ferromagnetic powder of the present invention preferably adopts chilling liquation alloy to make, especially, preferably with the liquation chilling of alloy, solidify and the chilling strip (band) that obtains is pulverized and made.Below, an example of its manufacture method is described.
Fig. 4 represents to use the quench of single roller to make the oblique view of configuration example of the device (chilling strip manufacturing installation) of ferromagnetic material, and Fig. 5 is the alloy liquation in the device shown in Figure 4 carries out a section side view from the state of colliding part to chill roll.
As shown in Figure 4, chilling strip manufacturing installation 1 possesses the cylindrical shell 2 and the chill roll 5 of relative this cylindrical shell 2 along the direction rotation of arrow 9A among the figure that can hold ferromagnetic material.Lower end at cylindrical shell 2 forms the nozzle (aperture) 3 that sprays ferromagnetic material (alloy) liquation.
In addition, around near the nozzle 3 of cylindrical shell 2, the coil 4 of configuration heating usefulness on this coil 4, for example by applying high-frequency current, with heating (induction heating) in the cylindrical shell 2, makes the ferromagnetic material in the cylindrical shell 2 be in molten state.
Chill roll 5 is made of base portion 51 and the superficial layer 52 that forms the periphery 53 of chill roll 5.
The constituent material of base portion 51 can use the formation of the material integral body identical with superficial layer 52, also can use the material different with superficial layer 52 to constitute in addition.
The constituent material of base portion 51 has no particular limits, and preferably for example is made of copper or the such high metal material of thermal conductivity of copper alloy, so that the heat energy of superficial layer 52 enough promptly leaves.
In addition, superficial layer 52 is preferably equated with base portion 51 by thermal conductivity or constitutes than base portion 51 low materials.As the object lesson of superficial layer 52, can enumerate thin metal layer or metal oxide layer or potteries such as Cr.
As pottery, for example can enumerate Al 2O 3, SiO 2, TiO 2, Ti 2O 3, ZrO 2, Y 2O 3, oxide based pottery such as barium titanate, strontium titanates, AlN, Si 3N 4, nitride based potteries such as TiN, BN, graphite, SiC, ZrC, Al 4C 3, CaC 2, carbonization system pottery such as WC, perhaps the composite ceramics 2 kind or more of combination in any among them.
Such chilling strip manufacturing installation 1 is arranged in the chamber (not shown), carries out work under this indoor state of preferably filling inert gas or other atmosphere gas.Especially, in order to prevent the oxidation of chilling strip 8, atmosphere gas is inert gases such as argon gas, helium, nitrogen preferably.
In chilling strip manufacturing installation 1, ferromagnetic material (alloy) is put into cylindrical shell 2, utilize coil 4 to heat and melt, from nozzle 3 ejection alloy liquations 6, as shown in Figure 5, the periphery 53 of alloy liquation 6 collision chill rolls 5, after forming hydrops 7, on the periphery 53 of chill roll 5 of rotation, spin out on one side, on one side quench cooled and solidifying, chilling strip 8 formed continuously or intermittently.The chilling strip 8 of Xing Chenging leaves its roll surface 81 from periphery 53 soon like this, advances along the direction of the arrow 9B among Fig. 4.In Fig. 5, be represented by dotted lines the freezing interface 71 of alloy liquation.
The peripheral speed of chill roll 5, according to the composition of alloy liquation, the wetability of 53 pairs of alloy liquations 6 of periphery etc., its suitable scope is different, in order to improve magnetic property, better is 1～60m/s usually, preferably 5～40m/s.If the peripheral speed of chill roll 5 is slow excessively, the volume flow (volume of the alloy liquation that time per unit spued) that depends on chilling strip 8, the thickness t thickening of chilling strip 8, the tendency that crystal grain diameter increases appears, on the contrary, if the peripheral speed of chill roll 5 is too fast, major part becomes noncrystal tissue, no matter any situation even heat-treat later on, can not expect to improve magnetic property.
To the chilling strip 8 that obtains, for example, also can carry out at least 1 heat treatment in order to promote the homogenizing that recrystallizes, organizes of noncrystal tissue.As this heat treated condition, for example can carry out about 0.5～300 minute at 400～900 ℃.
In addition, for anti-oxidation, this heat treatment is preferably under vacuum or the decompression state (for example 1 * 10 -1～1 * 10 -6Hold in the palm) or in the non-oxidizing atmosphere as inert gases such as nitrogen, argon gas, helium, carry out.
The chilling strip (ferromagnetic material of thin ribbon shaped) 8 that adopts above manufacture method to obtain forms fine grain structure or comprise the compact grained tissue in noncrystal tissue, thereby obtains good magnetic property.Then this chilling strip 8 is pulverized, just obtained ferromagnetic powder of the present invention.
The method of pulverizing has no particular limits, and for example can use various reducing mechanisms, breakers such as ball mill, vibrating mill, injector-type mill, draw point grinder to carry out.At this moment, for anti-oxidation, also can be under vacuum or decompression state (for example 1 * 10 -1～1 * 10 -6Hold in the palm) or in the non-oxidizing atmosphere as inert gases such as nitrogen, argon gas, helium, pulverize.
The average grain diameter of ferromagnetic powder has no particular limits, in the occasion that is used to make isotropism binding magnet described later, consider to prevent the oxidation of ferromagnetic powder and the magnetic property deterioration that produces by pulverizing, the average grain diameter of ferromagnetic powder better is about 0.5～150 μ m, be more preferably about 0.5～80 μ m, preferably about 1～50 μ m.
In addition, the better formability when being shaped in order to obtain binding magnet, the particle size distribution of ferromagnetic powder preferably has dispersion (fluctuation) to a certain degree.Thus, can lower the porosity of resulting binding magnet, its result when the content of the ferromagnetic powder in binding magnet is identical, can more improve the density or the mechanical strength of binding magnet, can improve magnetic property more.
To the ferromagnetic powder that obtains, for example influence, the control crystal grain diameter in order to remove the strain that is caused by pulverizing also can be heat-treated.As heat treated condition,, carried out about 0.5～300 minute for example at 350～850 ℃.
In addition, for anti-oxidation, this heat treatment is preferably under vacuum or the decompression state (for example 1 * 10 -1～1 * 10 -6Hold in the palm) or in the non-oxidizing atmosphere as inert gases such as nitrogen, argon gas, helium, carry out.
When using above ferromagnetic powder to make binding magnet, the such ferromagnetic powder and the adhesiveness of binder resin (wetability of binder resin) well, therefore, the mechanical strength height of this binding magnet, thermal stability (thermal endurance), corrosion resistance are good.Therefore, this ferromagnetic powder is suitable for making binding magnet.
More than, as quench,, also can adopt double roller therapy though single-roller method has been described for example.In addition, in addition, for example also can adopt as atomizations such as gas atomization, rotating disk method, melt extraction method, mechanical alloying (MA) method etc. and make.Such quench can make metal structure (crystal grain) refinement, is effective to the magnetic property, particularly coercive force etc. that improve binding magnet therefore.
Binding magnet and manufacturing thereof
Then, isotropism binding magnet of the present invention (below, be called " binding magnet " simply) is described.
Binding magnet of the present invention preferably constitutes with the above-mentioned ferromagnetic powder of binder resin bonding.
As binder resin (adhesive), can be any of thermoplastic resin, thermosetting resin.
As thermoplastic resin, for example can enumerate polyamide (as nylon 6, nylon 46, nylon 66, NYLON610, nylon 612, nylon 11, nylon 12, nylon 6-12, nylon 6-66), thermoplastic polyimide, liquid crystal polymers such as aromatic polyester, polyphenylene oxide, polyphenylene sulfide, polyethylene, polypropylene, polyolefin such as vinyl-vinyl acetate copolymer, improved polyalkene, Merlon, polymethyl methacrylate, PETG, polyester such as polybutylene terephthalate (PBT), polyethers, polyether-ether-ketone, Polyetherimide, polyacetals etc., perhaps based on their copolymer, admixture, polymer alloies etc. can use mixing more than a kind or 2 kinds in them.
Wherein,, mechanical strength high consideration good especially from formability, polyamide is preferably considered from improving the thermal endurance aspect, preferably based on the thermoplastic resin of liquid crystal polymer, polyphenylene sulfide.In addition, the mixing property of these thermoplastic resins and ferromagnetic powder is also good.
Such thermoplastic resin is because differences such as its kind, copolymerizationization have the advantage of the selection of energy wide region, so that for example pay attention to formability or pay attention to thermal endurance, mechanical strength.
On the other hand, as thermosetting resin, for example can enumerate various epoxy resin such as bisphenol type, linear phenol-aldehyde resin, naphthalene system, phenolic resins, urea resin, melmac, polyester (unsaturated polyester (UP)) resin, polyimide resin, silicones, polyurethane resin etc. can use mixing more than a kind or 2 kinds among them.
Wherein, from have excellent moldability, mechanical strength height, excellent heat resistance aspect are considered, are good with epoxy resin, phenolic resins, polyimide resin, silicones, with epoxy resin the best.In addition, the mixing property of these thermosetting resins and ferromagnetic powder, mixing uniformity are all good.
Employed thermosetting resin (uncured) can be aqueous in room temperature, also can be solid shape (Powdered).
Such binding magnet of the present invention is for example made as following.With ferromagnetic powder and binder resin and the additive (preventing oxidant, lubricant etc.) that uses as required mix, mixing (for example, mixing between temperature), make binding magnet composition (mixture), use this binding magnet composition, adopt manufacturing process such as compression molding (press forming), extrusion molding, injection moulding, in no magnetic field, be configured as desirable magnet shape.When binder resin is thermosetting resin, after the shaping, utilizes heating to wait and make its curing.
At this, in 3 kinds of above-mentioned manufacturing process, the degree of freedom that extrusion molding and injection moulding (especially injection moulding) have the shape selection is big, the productivity ratio advantages of higher, but in these manufacturing process, in order to obtain good formability, must guarantee the abundant flowability of the mixture in the forming machine, therefore compare with compression molding, can not make the content of ferromagnetic powder many, promptly can not make binding magnet carry out densification.But the present invention can obtain high magnetic flux density as described later, even thereby do not make the binding magnet densification, also can obtain good magnetic property, therefore in the binding magnet that adopts extrusion molding, injection moulding manufacturing, also can enjoy its advantage.
The content of the ferromagnetic powder in the binding magnet (containing ratio) has no particular limits, and considers usually that manufacturing process or formability and high magnetic characteristics are existed side by side to decide.Specifically, better be about 75～99.5 weight %, preferably about 85～97.5 weight %.
Especially, when adopting compression molding to make binding magnet, the content of ferromagnetic powder better is about 90～99.5 weight %, preferably about 93～98.5 weight %.
When adopting extrusion molding or injection moulding to make binding magnet, the content of ferromagnetic powder better is about 75～98 weight %, preferably about 85～97 weight %.
The density p of binding magnet is by factor decisions such as the content of the proportion of the ferromagnetic powder that contains in the binding magnet, ferromagnetic powder, porositys.In binding magnet of the present invention, its density p has no particular limits, but better is 5.3～6.6Mg/m 3About, 5.5～6.4Mg/m preferably 3About.
Therefore in the present invention, the magnetic flux density of ferromagnetic powder is big, coercive force is big, and when being configured as binding magnet, no matter how still less the content of ferromagnetic powder is, all obtains good magnetic property (especially high maximum magnetic energy product (BH) max).
The shape of binding magnet of the present invention, size etc. have no particular limits, for example shape can be cylindric, prism-shaped, cylindric (ring-type), circular-arc, tabular, crooked all tabular etc. shapes, and its size also can be to subminiature all sizes from large-scale.Especially be favourable to miniaturization, subminiaturized magnet, this point is repeatedly mentioned in this manual.
Hence one can see that, and binding magnet of the present invention is preferably supplied with multipole magnetized, perhaps by multipole magnetized.
Such binding magnet preferably satisfies the condition of the following stated.
(1) coercive force of binding magnet (the intrinsic coercive force under the room temperature) H CJBe 320～720kA/m 3Especially preferably 400～640kA/m 3During less than above-mentioned lower limit, according to the purposes of motor, the demagnetization when applying counter magnetic field is remarkable at coercive force, and also deterioration of the thermal endurance during high temperature.In addition, if coercive force surpasses above-mentioned higher limit, magnetizability just reduces.Therefore, by with coercive force H CJBe defined in above-mentioned scope, on binding magnet (especially cylinder-shaped magnet), carry out the occasion of multipole magnetized grade, even when can not get sufficient magnetizing field, also can carry out good magnetization, obtain sufficient magnetic flux density, thereby can provide high performance binding magnet, especially the motor binding magnet.
(2) binding magnet is at maximum magnetic energy product described later (BH) max[kJ/m 3] and density p (Mg/m 3) between preferably satisfy following formula (I).
2.2≤(BH)max/ρ 2[×10 -9J·m 3/g 2]......(I)
In addition, replacement formula (I) better is to satisfy formula (II), preferably satisfies formula (III).
2.3≤(BH)max/ρ 2[×10 -9J·m 3/g 2]≤3.2......(II)
2.4≤(BH)max/ρ 2[×10 -9J·m 3/g 2]≤3.1......(III)
(BH) max/ ρ 2[* 10 -9Jm 3/ g 2] value during less than the lower limit in the above-mentioned formula, if do not improve the density of magnet, promptly do not improve the content (containing ratio) of ferromagnetic powder, just can not get sufficient magnetic characteristic.Under these circumstances, the problem that causes the restriction, expensiveization of manufacturing process, the formability that causes by the minimizing of binder resin to reduce.In addition, in order to obtain certain magnetic characteristic, volume will increase, and it is difficult that the miniaturization of machine becomes.
(3) binding magnet, residual magnetic flux density Br[T at room temperature] and density p (Mg/m 3) between satisfy following formula (IV).
0.125≤Br/ρ[×10 -6T·m 3/g]......(IV)
Replacement formula (IV) better is to satisfy formula (V), preferably satisfies formula (VI).
0.128≤Br/ρ[×10 -6T·m 3/g]≤0.16......(V)
0.13≤Br/ρ[×10 -6T·m 3/g]≤0.155......(VI)
Br/ ρ [* 10 -6Tm 3/ g] value during less than the lower limit in the above-mentioned formula, if do not improve the density of magnet, promptly do not improve the content (containing ratio) of ferromagnetic powder, just can not get sufficient magnetic flux density.Under these circumstances, cause the restriction, expensiveization of manufacturing process or the problem that reduces by the formability that the minimizing of binder resin causes.In addition, in order to obtain certain magnetic flux density, volume will increase, and it is difficult that the miniaturization of machine becomes.
(4) maximum magnetic energy product of binding magnet (BH) max better is 60kJ/m 3More than, be more preferably 65kJ/m 3More than, 70～130kJ/m preferably 3If max is less than 60kJ/m for maximum magnetic energy product (BH) 3, motor with in when using, according to its kind, structure, can not get enough torques.
(5) binding magnet, the absolute value of irreversible demagnetization rate (initial stage demagnetization rate) better is below 6.2%, is more preferably below 5%, preferably below 4%.Thus, obtain the good binding magnet of thermal stability (thermal endurance).
Below, specific embodiments of the invention are described.
Embodiment 1
It is (Nd that the method for employing the following stated obtains alloy composition 0.7Pr 0.25Dy 0.05) 8.7Fe SurplusCo 7.0B 5.6Nb wFerromagnetic powder (7 kinds of ferromagnetic powders that Nb content w is different).
At first, weighing Nd, Pr, Dy, Fe, Co, B, the various raw materials of Nb are cast as mother alloy ingot, cut the test portion of about 15g from this ingot casting.
The chilling strip manufacturing installation 1 of set-up dirgram 4 and formation shown in Figure 5 is put into the bottom with above-mentioned test portion and is provided with nozzle (circular hole aperture: 3 quartz ampoule orifice diameter 0.55mm).After making the indoor degassing of holding chilling strip manufacturing installation 1, import inert gas (argon gas), form the atmosphere of temperature desired and pressure.
The chill roll (diameter 200mm) of the superficial layer 52 that about 5 μ m that chill roll 5 uses the periphery setting at copper base portion 51 to be made of WC are thick.
After this, utilize high-frequency induction heating that the ingot casting test portion in the quartz ampoule is melted, the peripheral speed of (the interior pressure of quartz ampoule and the pressure reduction of atmosphere pressures), chill roll is pressed in the injection of adjusting the alloy liquation again, makes the chilling strip.
After the chilling strip coarse crushing that obtains, in argon gas atmosphere, carry out the heat treatment of 710 ℃ * 300s, obtain ferromagnetic powder.
Then,, use pulverizer (pulverizing mill), in argon gas, this ferromagnetic powder is further pulverized, form the ferromagnetic powder of average grain diameter 50 μ m in order to adjust granularity.
For the ferromagnetic powder that obtains, in order to analyze its phase composition, use Cu-K α, carry out X-ray diffraction for 20 °～60 ° with the angle of diffraction.Can confirm hard magnetic phase R from diffraction pattern 2(FeCo) 14Type B reaches mutually that soft magnetism phase α-(result according to observing with transmission electron microscope (TEM) can confirm to form complex tissue (nano combined tissue) for Fe, the Co) diffraction maximum of type phase.
Mixed polyamide resin in this ferromagnetic powder (nylon 12), a spot of hydrazine system prevents oxidant and lubricant, and it is carried out 225 ℃ * 15 minutes mixing, makes binding magnet with composition (mixture).At this moment, the cooperation ratio (weight ratio) of ferromagnetic powder and polyamide (nylon 12) is defined as about equally value for each binding magnet.The content (containing ratio) that is the ferromagnetic powder in each binding magnet approximately is 97 weight %.
Then, this mixture is ground into granular, this shot-like particle of weighing, be filled in the metal pattern of pressure setting, 210 ℃ of temperature, carry out compression molding (in no magnetic field) with pressure 800MPa, obtain the columned isotropism binding magnet of diameter 10mm * high 7mm.
After these binding magnets being implemented the impulse magnetization of magnetic field intensity 3.2MA/m, (eastern English industry (strain) system TRF-5BH), is measured magnetic property (residual magnetic flux density Br, coercive force H with maximum externally-applied magnetic field 2.0MA/m to use direct current self-recording fluxmeter CJ, maximum magnetic energy product (BH) max).Temperature during mensuration is 23 ℃ (room temperatures).
Then, carry out stable on heating test.Binding magnet after keeping under the environment of 100 ℃ * 1h, is measured the irreversible demagnetization rate (initial stage demagnetization rate) when returning room temperature, estimate its thermal endurance.The absolute value of irreversible demagnetization rate (initial stage demagnetization rate) is more little, and thermal endurance (thermal stability) is good more.
About each binding magnet, Nb content w, density p, residual magnetic flux density Br, coercive force H CJ, maximum magnetic energy product (BH) max and irreversible demagnetization rate value be shown in Table 1.
Clearly illustrate that as table 1 binding magnet of sample No.2～No.6 (the present invention) all has good magnetic property (residual magnetic flux density Br, maximum magnetic energy product (BH) max and coercive force H CJ), the irreversible demagnetization rate is little simultaneously, and thermal stability (thermal endurance) is also good.
In contrast, the binding magnet of sample No.1, No.7 (comparative example), the magnetic property deterioration, simultaneously, the absolute value of irreversible demagnetization rate is big, and thermal stability is also low.
Embodiment 2
Operate in the same manner with embodiment 1, obtaining alloy composition is (Nd 0.75Pr 0.2Dy 0.05) 8.9Fe SurplusCo 6.9B 5.5Nb 1.5Ferromagnetic powder.
Mixed polyamide resin in the ferromagnetic powder that obtains (nylon 12), a spot of hydrazine system prevents oxidant and lubricant, and it is carried out 200～230 ℃ * 15 minutes mixing, makes binding magnet with composition (mixture).At this moment, change the ferromagnetic powder content (containing ratio) in the binding magnet powder, obtain 7 kinds of mixtures.
In the mixture that obtains like this, the mixture that the content of ferromagnetic powder is more be ground into granular after, under no magnetic field, carry out compression molding, the mixture that the content of ferromagnetic powder is less be ground into granular after, under no magnetic field, carry out injection moulding, make binding magnet.
The size of binding magnet all is the cylindric of diameter 10mm * high 7mm.
Shot-like particle is filled in the metal pattern of pressure setting,, carries out compression molding with pressure 800MPa 210～220 ℃ of temperature.Make the metal pattern temperature when being shaped reach 90 ℃, the interior temperature of injection barrel reaches 230～280 ℃ and carries out injection moulding.
Each binding magnet that obtains for such making carries out the mensuration and the heat-resistance test of magnetic property in the same manner with embodiment 1.
About each binding magnet, melting temperature, manufacturing process, forming temperature, density p, residual magnetic flux density Br, coercive force H CJ, maximum magnetic energy product (BH) max and irreversible demagnetization rate value be shown in Table 2.
Clearly illustrate that as table 2 binding magnet of the present invention has good magnetic property (residual magnetic flux density Br, maximum magnetic energy product (BH) max and coercive force (H in wide density p scope CJ)), simultaneously, the irreversible demagnetization rate is little, and thermal stability (thermal endurance) is also good.
Especially, even binding magnet of the present invention also has good magnetic property under the situation of the low-density binding magnet (content of ferromagnetic powder is few) that adopts injection moulding to obtain, this is because following reason is arranged.
Low-density, promptly the content of binder resin for a long time, when mixing or the flowability of the mixture when being shaped uprise.Therefore, ferromagnetic powder and binder resin carry out the mixing possibility that becomes, easy homogenizing when mixing in lower temperature, with the short time.In addition, if the flowability of mixture is high, forming easily in lower temperature, with the short time also becomes possibility.That is, can relax molding condition.Its result, the deterioration (oxidation etc.) of ferromagnetic powder that can be when mixing, when being shaped is suppressed to minimum, obtains the binding magnet of high magnetic characteristics thus, and formability also improves.
In addition,, just can reduce the porosity of resulting binding magnet, when improving mechanical strength, also improve magnetic property thus if mixture is mobile high.
Embodiment 3
Each ferromagnetic powder that uses embodiment 1 to obtain is operated in the same manner with embodiment 1, makes the isotropism binding magnet of external diameter 22mm * internal diameter 20mm * high 4mm cylindric (ring-type), and resulting each binding magnet carries out multipole magnetized at 8 utmost points.During magnetization, the current value that flows through magnetizing coil is 16kA.
At this moment, in order to reach the big or small smaller of magnetic susceptibility 90% needed magnetizing field, so magnetizability is good.
Use and carried out magnetized each binding magnet like this, assembling CD-ROM spindle drive motor as rotor magnet.
Use in the spindle drive motor counter voltage that takes place in the coiling coil when measuring with the 1000rpm rotor at each CD-ROM.Its result, use the motor of the binding magnet of sample No.1, No.7 (all being comparative example), voltage is below the 0.80V, in contrast, use the motor of the binding magnet of sample No.2～No.6 (the present invention), all obtain the above and 20% above high value of 0.96V.
The result shows, uses binding magnet of the present invention can make high performance motor.
Make the binding magnet (containing ratio of the ferromagnetic powder in the binding magnet: 92～95 weight %) except adopting extrusion molding, make binding magnet of the present invention and motor in the same manner with the foregoing description 1～3, carry out performance evaluation, obtain and above-mentioned identical result.
Make the binding magnet (containing ratio of the ferromagnetic powder in the binding magnet: 90～93 weight %) except adopting injection moulding, make binding magnet of the present invention and motor in the same manner with the foregoing description 1～3, carry out performance evaluation, obtain and above-mentioned identical result.
As previously discussed, obtain following effect according to the present invention.
Ferromagnetic powder contains the Nb of ormal weight, and has soft magnetism phase and hard magnetic complex tissue mutually, and magnetization is high thus, brings into play good magnetic property, and intrinsic especially coercive force and rectangularity improve.
The absolute value of irreversible demagnetization rate is little, obtains good thermal endurance (thermal stability).
Therefore isotropism obtains high magnetic flux density, even also can obtain having the binding magnet of high magnetic characteristics.Especially compare with isotropism binding magnet in the past, can be with the equal above magnetic property of the binding magnet of littler volume performance, therefore obtain high performance motor and become possibility with more small-sized.
In addition, owing to obtain high magnetic flux density, therefore when making binding magnet, even do not pursue densification, also can access fully high magnetic property, its result is when formability improves, seek dimensional accuracy, mechanical strength, corrosion resistance, thermal endurance (thermal stability) etc. and further improve, easily the high binding magnet of fabrication reliability.
Therefore magnetizability is good, can magnetize with lower magnetizing field, especially can be easily and carry out multipole magnetizedly etc. reliably, and can access high magnetic flux density.
Owing to do not require densification, therefore can adopt to compare to be difficult for carrying out extrusion molding method or the injection moulding manufactured binding magnet that high density is shaped, even the binding magnet that is shaped with such forming process also obtains the above-mentioned effect of picture with compression forming method.Therefore, the range of choice of the manufacturing process of binding magnet is wide, and the degree of freedom of being selected by the shape that these manufacturing process produce is also big.
Table 1
Sample No. W ρ (Mg/m 3) Br (T) H cJ (kA/m) (BH)max (kJ/m 3) (BH)max/ρ 2 (×10 -9J·m 3/g 2) Br/ρ (×10 -6T·m 3/g) Irreversible demagnetization rate (%)
1 (comparative example) 0.1 6.27 0.83 345 75.6 1.92 0.132 -6.5
2 (the present invention) 0.2 6.26 0.87 415 104.8 2.67 0.139 -4.7
3 (the present invention) 0.5 6.32 0.90 478 113.2 2.83 0.142 -4.0
4 (the present invention) 1.2 6.29 0.92 496 115.9 2.93 0.146 -3.6
5 (the present invention) 2.5 6.30 0.90 530 112.0 2.82 0.143 -3.2
6 (the present invention) 3.3 6.33 0.81 561 102.7 2.56 0.128 -2.7
7 (comparative examples) 3.6 6.31 0.76 553 79.1 1.99 0.120 -3.5
Table 2
Sample No. Melting temperature (℃) Manufacturing process Forming temperature (℃) ρ (Mg/m 3) Br (T) H cJ (kA/m) (BH)max (kJ/m 3) (BH)max/ρ 2 (×10 -9J·m 3/g 2) Br/ρ (×10 -6T·m 3/g) Irreversible demagnetization rate (%)
8 (the present invention) 220 Injection moulding 230 5.30 0.78 563 83.4 2.97 0.147 -2.2
9 (the present invention) 203 Injection moulding 245 5.50 0.80 551 88.3 2.92 0.146 -2.5
10 (the present invention) 211 Injection moulding 260 5.67 0.82 542 92.6 2.88 0.145 -2.9
11 (the present invention) 216 Injection moulding 275 5.80 0.84 535 96.2 2.86 0.144 -3.1
12 (the present invention) 220 Compression molding 210 5.95 0.85 531 100.5 2.84 0.143 -3.4
13 (the present invention) 224 Compression molding 215 6.21 0.88 517 108.8 2.82 0.142 -3.7
14 (the present invention) 230 Compression molding 220 6.48 0.92 510 118.4 2.82 0.142 -4.2

Claims (23)

1. ferromagnetic powder, it is by with R x(Fe 1-yCo y) 100-x-z-wB zNb wThe alloy composition of expression constitutes, wherein R is at least a rare earth element, x:7.1～9.9 atom %, y:0～0.30, z:4.6～6.9 atom %, w:0.2～3.5 atom %, this ferromagnetic powder constitutes with hard magnetic complex tissue mutually mutually by having soft magnetism, it is characterized in that, forming density p [Mg/m with forming after binder resin mixes 3] the isotropism binding magnet time, maximum magnetic energy product at room temperature (BH) max[kJ/m 3] satisfied (BH) max/ ρ 2[* 10 -9Jm 3/ g 2The relation of] 〉=2.2, and the intrinsic coercive force H under the room temperature CJBe 320～720kA/m.
2. the described ferromagnetic powder of claim 1 wherein, is forming density p [Mg/m with forming after binder resin mixes 3] the isotropism binding magnet time, the residual magnetic flux density Br[T under the room temperature] satisfy Br/ ρ [* 10 -6Tm 3/ g] 〉=0.125 relation.
3. ferromagnetic powder, it is by with R x(Fe 1-yCo y) 100-x-z-wB zNb wThe alloy composition of expression constitutes, wherein R is at least a rare earth element, x:7.1～9.9 atom %, y:0～0.30, z:4.6～6.9 atom %, w:0.2～3.5 atom %, this ferromagnetic powder constitutes with hard magnetic complex tissue mutually mutually by having soft magnetism, it is characterized in that, forming density p [Mg/m with forming after binder resin mixes 3] the isotropism binding magnet time, the residual magnetic flux density Br[T under the room temperature] satisfy Br/ ρ [* 10 -6Tm 3/ g] 〉=0.125 relation.
4. the described ferromagnetic powder of claim 3, wherein, with form when forming the isotropism binding magnet the intrinsic coercive force H under the room temperature after binder resin mixes CJBe 320～720kA/m.
5. the described ferromagnetic powder of each in the claim 1～4, wherein, ferromagnetic powder with form after binder resin mixes when forming isotropic magnet, the absolute value of irreversible demagnetization rate is below 6.2%.
6. the described ferromagnetic powder of each in the claim 1～4, wherein, above-mentioned R is the rare earth element based on Nd and/or Pr.
7. the described ferromagnetic powder of each in the claim 1～4, wherein, above-mentioned R comprises Pr, and above-mentioned relatively R is all, and its ratio is 5～75%.
8. the described ferromagnetic powder of each in the claim 1～4, wherein, above-mentioned R comprises Dy, and above-mentioned relatively R is all, and its ratio is below 14%.
9. the described ferromagnetic powder of each in the claim 1～4, wherein, ferromagnetic powder obtains by the quick cooling alloy liquation.
10. the described ferromagnetic powder of each in the claim 1～4, wherein, ferromagnetic powder is pulverized the chilling strip that uses chill roll to make and is obtained.
11. the described ferromagnetic powder of each in the claim 1～4, wherein, ferromagnetic powder carries out at least 1 heat treatment in its manufacture process or after manufacturing.
12. the described ferromagnetic powder of each in the claim 1～4, wherein, the average grain diameter of ferromagnetic powder is 0.5～150 μ m.
13. an isotropism rare-earth bound magnet, it is to constitute with the ferromagnetic powder that binder resin bonding contains Nb, and this ferromagnetic powder is by with R x(Fe 1-yCo y) 100-x-z-wB zNb wThe alloy composition of expression constitutes, wherein R is at least a rare earth element, x:7.1～9.9 atom %, y:0～0.30, z:4.6～6.9 atom %, w:0.2～3.5 atom %, this ferromagnetic powder constitutes with hard magnetic complex tissue mutually mutually by having soft magnetism, it is characterized in that, be ρ [Mg/m in the density of isotropism binding magnet 3] time, the maximum magnetic energy product under the room temperature (BH) max[kJ/m 3] value satisfy (BH) max/ ρ 2[* 10 -9Jm 3/ g2] 〉=2.2 relation, and the intrinsic coercive force H under the room temperature CJBe 320～720kA/m.
14. the described isotropism binding magnet of claim 13, wherein, the residual magnetic flux density Br[T under the room temperature] satisfy Br/ ρ [* 10 -6Tm 3/ g] 〉=0.125 relation.
15. an isotropism rare-earth bound magnet, it is to constitute with the ferromagnetic powder that binder resin bonding contains Nb, and this ferromagnetic powder is by with R x(Fe 1-yCo y) 100-x-z-wB zNb wThe alloy composition of expression constitutes, wherein R is at least a rare earth element, x:7.1～9.9 atom %, y:0～0.30, z:4.6～6.9 atom %, w:0.2～3.5 atom %, this ferromagnetic powder constitutes with hard magnetic complex tissue mutually mutually by having soft magnetism, it is characterized in that, be ρ [Mg/m in the density of isotropism binding magnet 3] time, the residual magnetic flux density Br[T under the room temperature] satisfy Br/ ρ [* 10 -6Tm 3/ g] 〉=0.125 relation.
16. the described isotropism binding magnet of claim 15, wherein, the intrinsic coercive force H under the room temperature CJBe 320～720kA/m.
17. the described isotropism binding magnet of each in the claim 13～16, wherein, above-mentioned R is the rare earth element based on Nd and/or Pr.
18. the described isotropism binding magnet of each in the claim 13～16, wherein, above-mentioned R comprises Pr, and above-mentioned relatively R is all, and its ratio is 5～75%.
19. the described isotropism binding magnet of each in the claim 13～16, wherein, above-mentioned R comprises Dy, and above-mentioned relatively R is all, and its ratio is below 14%.
20. the described isotropism binding magnet of each in the claim 13～16, wherein, the average grain diameter of above-mentioned ferromagnetic powder is 0.5～150 μ m.
21. the described isotropism binding magnet of each in the claim 13～16, wherein, the absolute value of irreversible demagnetization rate is below 6.2%.
22. the described isotropism binding magnet of each in the claim 13～16, this magnet are supplied with multipole magnetized or by multipole magnetized.
23. the described isotropism binding magnet of each in the claim 13～16, this magnet is used for motor.
CNB011108142A 2000-01-06 2001-01-06 Magnet powder and isotropic bound magnet Expired - Fee Related CN1172326C (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2000000927A JP2001196211A (en) 2000-01-06 2000-01-06 Magnet powder and isotropic bond magnet
JP927/2000 2000-01-06

Publications (2)

Publication Number Publication Date
CN1304144A CN1304144A (en) 2001-07-18
CN1172326C true CN1172326C (en) 2004-10-20

Family

ID=18530200

Family Applications (1)

Application Number Title Priority Date Filing Date
CNB011108142A Expired - Fee Related CN1172326C (en) 2000-01-06 2001-01-06 Magnet powder and isotropic bound magnet

Country Status (6)

Country Link
US (1) US20010039980A1 (en)
EP (1) EP1115127B1 (en)
JP (1) JP2001196211A (en)
KR (1) KR100363371B1 (en)
CN (1) CN1172326C (en)
TW (1) TW533435B (en)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1061533B1 (en) 1999-06-11 2006-09-27 Seiko Epson Corporation Magnetic powder and isotropic bonded magnet
JP3593939B2 (en) 2000-01-07 2004-11-24 セイコーエプソン株式会社 Magnet powder and isotropic bonded magnet
JP4243413B2 (en) * 2000-05-31 2009-03-25 セイコーエプソン株式会社 Magnet powder manufacturing method and bonded magnet manufacturing method
CN1182548C (en) * 2000-07-10 2004-12-29 株式会社新王磁材 Rear-earth magnet and its producing method
TW200536788A (en) * 2004-05-07 2005-11-16 Spin Technology Corp Magnetic material containing praseodymium
EP2394351B1 (en) * 2009-02-05 2020-08-05 Evr Motors Ltd. Electrical machine
JP6634018B2 (en) 2013-09-18 2020-01-22 イー．ヴィー．アール． モーターズ リミテッドＥ．Ｖ．Ｒ． Ｍｏｔｏｒｓ Ｌｔｄ． Multi-pole electric machine

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01103805A (en) * 1987-07-30 1989-04-20 Tdk Corp Permanent magnet
JP3490228B2 (en) * 1996-03-25 2004-01-26 アルプス電気株式会社 Hard magnetic alloy compact and manufacturing method thereof
US5725792A (en) * 1996-04-10 1998-03-10 Magnequench International, Inc. Bonded magnet with low losses and easy saturation
JP3391704B2 (en) * 1998-06-15 2003-03-31 セイコーエプソン株式会社 Rare earth magnet
JP3275882B2 (en) * 1999-07-22 2002-04-22 セイコーエプソン株式会社 Magnet powder and isotropic bonded magnet
EP1061533B1 (en) * 1999-06-11 2006-09-27 Seiko Epson Corporation Magnetic powder and isotropic bonded magnet
JP3593940B2 (en) * 2000-01-07 2004-11-24 セイコーエプソン株式会社 Magnet powder and isotropic bonded magnet
JP3593939B2 (en) * 2000-01-07 2004-11-24 セイコーエプソン株式会社 Magnet powder and isotropic bonded magnet

Also Published As

Publication number Publication date
JP2001196211A (en) 2001-07-19
KR20010070441A (en) 2001-07-25
KR100363371B1 (en) 2002-12-05
TW533435B (en) 2003-05-21
EP1115127A3 (en) 2002-05-15
EP1115127A2 (en) 2001-07-11
EP1115127B1 (en) 2011-10-05
US20010039980A1 (en) 2001-11-15
CN1304144A (en) 2001-07-18

Similar Documents

Publication Publication Date Title
CN1172325C (en) Magnet powder and isotropic bound magnet
CN1155021C (en) Magnet powder and isotropy binding magnet
KR101855530B1 (en) Rare earth permanent magnet and their preparation
CN1228791C (en) Nanocomposite magnet
CN1212626C (en) Iron-based rare earth alloy nanocomposite magnet and method for producing the same
CN1163914C (en) Nitride type rare-earth permanent magnet material and bonded magnet using same
CN1183560C (en) Method for mfg ferromagnetic material, thin tape ferromagnetic material, ferromagnetic powder and bound magnet
CN1906713A (en) Iron base rare earth nano-composite magnet and method for production thereof
WO2006043348A1 (en) Method for producing rare earth permanent magnet material
CN1345073A (en) Manufacture and raw material powder of anisotropic magnetic powder and plastics magnet
CN1180442C (en) Magnetic powder, manufacture thereof and binded magnet
CN1282080A (en) Magnetic powder and isotropic binding magnet
CN1080920C (en) Iron-based permanent magnets and their fabrication as well as iron-based permanent magnet alloy powders for permanent banded magnets and iron-based bonded magents
CN1327889A (en) Cooled roller, thin strip shaped magnetic material, magnetic powder and adhesive magnet
CN1330372A (en) Magnet powder, manufacturing method for magnetic powder and binding magnet
CN1104014C (en) Process for production of magnet
CN1149591C (en) Magnetic powder and isotropy bound magnet
CN1246715A (en) Laminar rare earth-iron-boron-base magnetic alloy grain, its producing method and binding magnetic body produced by the alloy
CN1735947A (en) Nanocrystalline and nanocomposite rare earth permanent magnet materials and method of making the same
CN1193385C (en) Malgnet powder and istropic adhesive magnet
CN1172326C (en) Magnet powder and isotropic bound magnet
CN1237549C (en) Thin strip magnet material, magnet powder and rare earth bond magnet
CN1279485A (en) Magnetic powder and isotropic magnet
CN1208788C (en) Magnet powder and isotropic rare-earth adhesive magnet
CN115244206A (en) Iron-based rare earth boron isotropic magnet alloy

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C14 Grant of patent or utility model
GR01 Patent grant
CF01 Termination of patent right due to non-payment of annual fee
CF01 Termination of patent right due to non-payment of annual fee

Granted publication date: 20041020

Termination date: 20130106